Method of assembling an instrumentcontaining unit to a floating ship



June 20, 1967 o. R. KING 3,326,162

METHOD OF ASSEMBLING AN INSTRUMENT-CONTAINING UNIT TO A FLOATING SHIP Filed April 15, 1965 I 5 Sheets-Sheet 1 mun INVENTOR. OMAR R. KING BY MORGAN, FINNEGAN, DURHAM 8: PINE ATTORNEYS June 29, 1967 Filed April 15, 1965 O. R. KING METHOD OF ASSEMBLING AN INSTRUMENT-CONTAINING UNIT TO A FLOATING SHIP 5 Sheets-Sheet 2 INVENTOR. OMAR R. KING BY MORGAN, FINNEGAN, DURHAM 8 PINE ATTORNEYS o. R. KING 3,326,152 METHOD OF ASSEMBLING AN INSTRUMENT'CONTAINING June 20, 1967 UNIT TO A FLOATING SflIP Filed April 15, 1965 5 Sheets-Sheet INVENTOR. OMAR R. KINQ MORGAN, FINNEGAN, DURHAM 8 PINE ATTORNEYS June 20, 1967 O R KING 3,326,162 METHOD OF ASSEMBLING AN INSTRUMENT-CONTAININ Filed April 15, 1965 UNIT TO A FLOATING SHIP 6 Sheets-Sheet 4 INVENTOR. OMAR R. KING BY MORGAN, FINNEGAN, DURHAM 8 PINE ATTORNEYS June 29, 1967 o. R. KING 3,326,162

METHOD OF ASSEMBLING AN INSTRUMENT-CONTAINING UNIT TO A FLOATING SHIP Filed April 15, 1965 5 Sheets-Sheet F,

INVENTOR. OMAR R. KING BY MORGAN, FINNEGAN, DURHAM 8n PINE ATTORNEYS United States Patent O 3.326,162 METHOD OF ASSEMBLING AN INSTRUMENT- CONTAINING UNIT TO A FLOATING SHIP Omar R. King, West Bath, Maine, assignor to Bath Iron Works Corporation, Bath, Maine, a corporation of Maine Filed Apr. 15, 1965, Ser. No. 448,371 3 Claims. (Cl. 114-45) This invention relates generally to a method for securing a unit to a normally submerged portion of a ship, and relates more particularly to a method of assembling a sonar dome or other instrument-containing unit onto the submerged bow of a floating ship through the use of a floating partial dry dock.

It is desirable in certain instances to secure instrumentcontaining packages to a normally submerged portion of the hull of a ship while the ship is still under construction and, consequently, entirely out of the water. Frequently, however, units protruding below the hull are not convenient to install prior to launching due to interference with the ways and cradle supports during launching. Once a ship has been floated, moreover, it is an expensive and time-consuming operation to raise the ship out of the water. Therefore, when it has been desired to attach an instrument-containing unit to the submerged portion of a floating ship, the ship is brought to either a floating dry dock and raised entirely out of the water, or to a graving dock where the water is removed from around the ship. Accordingly, even when such units are comparatively small and require only a small portion of the ships hull for attachment thereto, their assembly onto a floating ship requires the use of a major facility, with its attendant high expense, and hampers normal work on the ship.

The method of assembling an instrument-containing unit to a floating ship in accordance with the present invention eliminates the foregoing disadvantages without disturbing the instrumentation by using a floating partial dry dock and closely controlling the buoyancy and trim of both the ship and the dock.

It is therefore an object of the present invention to provide a novel method for assembling a unit to a floating ship.

Another object of the invention is to provide a novel method for assembling an instrument-containing unit onto a normally submerged portion of a floating ship.

A further object of the invention is to provide a novel method for assembling a sonar dome or other instrumentcontaining unit to a normally submerged portion of a floating ship.

A still further object of the invention is to provide a novel method for assembling a sonar dome or other instrument-containing unit onto a submerged portion of a ship hull while the ship is floating in water through the use of a partial floating dry dock.

Objects and advantages of the invention are set forth in part herein and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

Briefly described, the present invention is directed toward a novel method of using a floating partial dry dock as a means for assembling an instrument-containing unit such as a sonar dome to a normally submerged portion of a ship hull while the ship is floating in water. This novel method utilizes a dry dock having a center section and two wing sections and a stern gate and includes the steps of: placing a sonar dome in the center section of the floating partial dry dock ballasted to an even keel condition; increasing the draft of the dock by flooding both the center and wing sections until the dock is submerged to a depth suflicient to float the dock into position beneath the hull portion of the ship to which the sonar dome is to be aflixed; decreasing the draft of the dock by evacuating the wing sections until the dock rises and seats in water sealed relation against the hull with the desired upload force; transferring the water from the center section to the wing sections, thereby maintaining the desired upload force; and evacuating the center section of water; affixing the sonar dome in position on the ship hull; increasing the draft of the clock by filling the center section from the wing tanks until the water in the center section is at the level of the water outside of the dock and thereafter flooding the wing tanks; thus increasing the draft of the dock; whereby the dock may be removed from under the ship.

Preferably, the dock has a stern gate movable from the horizontal position, to and from a vertical position where it engages the ship hull in water sealing relation. With this arrangement, the draft of the dock is decreased while the stern gate is in vertical position. Thereafter, when the sonar dome has been affixed to the ship hull, the stern gate is lowered to horizontal position when the draft of the dock is increased, whereby the dock may be easily removed from under the ship with increased clearance.

The invention consists in the novel steps, process, arrangements, combinations and improvements herein shown and described.

It will be understood that the foregoing general description and the following detailed description as well are exemplary and explanatory of the invention but are not restrictive thereof. Thus, while the method of this invention is particularly adapted to installing a sonar dome to the bow of a ship without placing the entire ship in dry dock, it will be apparent that the invention is not limited thereto, but encompasses the installation of other instrument-containing units to a normally submerged portion of a floating ship.

The accompanying drawings, referred to herein and constituting a parthereof, illustrate the steps or process. of the invention as applied to the installation of a sonar dome and, together with the description, serve to explain the principles of the invention.

Of the drawings:

FIGURE 1 is a side elevation, partly diagrammatic,-

of a floating partial dry dock, ballasted to an even keel condition and having a sonar dome placed therein;

FIGURE 2 is a fragmentary view in side elevation, partly diagrammatic, of the patrial dry dock illustrated in FIGURE 1, submerged and floated into position adjacent and beneath the hull portion of the ship to which the sonar dome is to be aflixed;

FIGURE 3 is a fragmentary view in side elevation, partly diagrammatic, of the partial dry dock illustrated in FIGURE 1 with a portion of the ballast removed permitting the dock to rise, locating the sonar dome more adjacent the hull portion to which it is to be affixed;

FIGURE 4 is a fragmentary view in side elevation, partly diagrammatic, illustrating the sonar dome affixed to the bow of a ship, and the dry dock resubmerged with the stern gate lowered to provide adequate clearance between the dome and the stern gate sill, permitting the dry dock to be floated out from under the ship; and

FIGURE 5 is an isometric view, partly diagrammatic, illustrating in a simplified manner, the partial dry dock of FIGURE 1 in place against the bow of a ship, with J the sonar dome aflixed to the bottom of the ships hull.

Referring now more particularly to the drawings, there is illustrated a floating partial dry dock, designated generally by reference numeral 10, having a control room 12, forward and after walkways 14 and 16, respectively, and a stern gate 18, adapted to be brought into watertight sealing engagement with the hull of a ship S, more fully explained hereinbelow.

Dry dock includes two water-tight wing tanks A and B on the port side and, similarly, two water-tight wing tanks C and D on the starboard side. Each of wing tanks A, B and C, D are separated by transverse bulkheads 19 and 20, respectively, and the two wing sections are separated by a center well section E.

Center section E of dry dock 10 carries the instrumentcontaining unit to be attached to a submerged portion of the hull of ship S, the unit being illustrated in the drawings as a sonar dome (The dome 25 is preferably mounted in the dry dock on suitable jacks (not shown) whereby the dome may be jacked into position on the ships hull when the dock has been floated under the ship. Alternatively, dome 25 may be lifted to the ships hull from the bottom of the dry dock by suitable lifting gear attached to the hull.

Four poppet supports are mounted, two on each wing section, forward and aft on the dry dock, only one of each pair being illustrated in the drawings, indicated by reference numerals and 32 (FIGURES 2 and 3) respectively, and are adapted to engage and seat in corresponding thrust-receiving brackets on each side of the ships hull.

It will be understood to those skilled in the art that the dry dock also includes, in suitable locations, the appropriate suction and discharge valves, piping, control cables, pumps, etc., for flooding and evacuating the center and wing sections so as to closely control the buoyancy and trim of the dock. Likewise, it will be understood that a suitable motorized winch and cable mechanism may be used to raise and lower the stern gate of the dock. Thus, it is intended that all the operating mechanisms for the dock be of substantially conventional construction, and for that reason they are not described in detail.

With reference particularly to FIGURES l-3 of the drawings, the method of attaching an instrument-containing unit to the submerged portion of a ship hull in accordance with the present invention is as follows:

The sonar dome is lowered and positioned on supporting jacks, or other supporting structures, in the center section of the floating partial dry dock, ballasted as required, and the dock floated to a position forward of the ship. The draft of the dock is then increased by opening a sea valve in the center section to permit free flooding and, additionally, by pumping sea water to the Wing sections until the dock is submerged to a depth sufficient to float under the ship. The dock is then floated into position adjacent and beneath the hull portion of the ship to which the sonar dome is to be attached.

The draft of the dock is then carefully decreased by pumping water from the wing tanks A, B, C and D.

only, until the four supporting poppets 30 and 32 engage and seat on thrust-receiving brackets of the ships hull. The evacuation of the wing tanks is continued until the stern gate 18 seals tightly against the ship and the desired upload force is achieved, evenly distributed between the four poppets. At this point, the center section is evacuated by pumping substantially all the water therein into the wing sections in equal portions. In this connection, it will be understood that, in order to maintain the upload force which has been achieved with the center section flooded, upon transferring the water in the center section to the wing sections it is necessary to pump a small portion of water overboard so as to compensate for the loss of buoyancy caused by the removal of the force exerted by the water in the center section against the ships hull.

With the center section dry, workers may enter the center section. The dome is jacked (or lifted) into position and affixed to the ships hull. During this assembling operation, the load on the jacks is carefully maintained equal to the weight of the dome. Just prior to unloading and removal of the jacks from the dome, additional sea water is pumped into the wing sections to increase the draft of the dock to compensate for the loss of the weight of the dome. Similarly, if the dome is lifted to the hull, water ballast is added to the wing tanks to compensate for the loss of the weight of the dome. Thus, the desired upload force is not exceeded at any time.

When it is desired to remove the partial dry dock, water is pumped into the center section from the wing sections until the water level in all of the sections is equalized and sufficient additional water is pumped from the wing sections to the center section until the water line of the center section is at sea level. At this point, the sea valve in the center section is opened and sea water is pumped to the wing sections until the dock reaches the required draft. The stem gate 18 is then lowered and the dock trimmed to provide adequate clearance between the dome and the stern gate sill (see FIGURE 4) as the dock is floated out from under the ship.

The invention in its broader aspects is not limited to the specific steps, process, constructions, and arrangements shown and described but departures may be made therefrom within the scope of the accompanying claims, without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is:

1. A method of assembling an instrument-containing unit such as a sonar dome or the like to a submerged portion of the hull of a ship while said ship is floating in water, comprising the steps of: placing the unit in the evacuated center section of a floating partial dry dock having wing sections ballasted as desired; increasing the draft of the dock by flooding both the center and wing sections until the dock is submerged to a depth sufficient to float the dock into position beneath the hull portion of the ship to which the unit is to be afiixed, decreasing the draft of the dock by evacuating the wing sections until the dock rises and seats against the, hull with a predetermined upload for ce; evacuating the center section of water; transferring substantially all of the water evacuated from the center section to the wing sections at a point above the waterline of the submerged dock so as to provide sufiicient ballast to maintain said predetermined upload force of said dock against said hull; affixing the unit in position on the ship hull; increasing the draft of the dock by flooding the center section, whereby the dock may be removed from under the ship and the attached unit.

2. A method of assembling an instrument-containing unit such as a sonar dome or the like to a submerged portion of the hull of a ship while said ship is floating in water, comprising the steps of: placing the unit in the evacuated center section of a floating partial dry dock having wing sections ballasted as desired and having a stern gate movable from a horizontal position to and from a vertical position for water-tight engagement with the hull; increasing the draft of the dock by flooding both the center and wing sections until the dock is submerged to a depth sufficient to float the dock into position beneath the hull portion of the ship to which the unit is to be aflfixed; decreasing the draft of the dock by evacuating the wing sections until the dock rises and seats against the hullwith a predetermined upload force; evacuating the center section of water; transferring substantially all of the water evacuated from the center section to the wing sections at a point above the waterline of the submerged dock so as to provide sufficient ballast to maintain said predetermined upload force of said dock against said hull; atfixing the unit in position on the ship hull; increasing the draft of the dock by filling the center section from the wing tanks until the water in the center section is at the level of 5 the water outside of the dock and thereafter flooding the Wing tanks; and lowering the gate to a horizontal position, whereby the dock may be removed from under the ship and the attached unit.

3. The method as claimed in claim 2, including, immediately preceding completion of the step of affixing the unit to the ship hull, the step of adding suflicient water to the wing tanks to increase the drafit of the dock to compensate for the loss of Weight of the unit.

6 References Cited UNITED STATES PATENTS 326,985 9/1885 Howes 6168 570,489 11/1896 Marsden 114-45 2,3 60,690 10/ 1944 Koulichkon 61-68 MILTON BUCHLER, Primary Examiner. ANDREW H. FARRELL, Examiner. 

1. A METHOD OF ASSEMBLING AN INSTRUMENT-CONTAINING UNIT SUCH AS A SONAR DOME OR THE LIKE TO A SUBMERGED PORTION OF THE HULL OF A SHIP WHILE SAID SHIP IS FLOATING IN WATER, COMPRISING THE STEPS OF: PLACING THE UNIT IN THE EVACUATED CENTER SECTION OF A FLOATING PARTIAL DRY DOCK HAVING WING SECTIONS BALLASTED AS DESIRED; INCREASING THE DRAFT OF THE DOCK BY FLOODING BOTH THE CENTER AND WING SECTIONS UNTIL THE DOCK IS SUBMERGED TO A DEPTH SUFFICIENT TO FLOAT THE DOCK INTO POSITION BENEATH THE HULL PORTION OF THE SHIP TO WHICH THE UNIT IS TO BE AFFIXED, DECREASING THE DRAFT OF THE DOCK BY EVACUATING THE WING SECTIONS UNTIL THE DOCK RISES AND SEATS AGAINST THE HULL WITH A PREDETERMINED UPLOAD FORCE; EVACUATING THE CENTER SECTION OF WATER; TRANSFERRING SUBSTANTIALLY ALL OF THE WATER EVACUATED FROM THE CENTER SECTION TO THE WING SECTIONS AT A POINT ABOVE THE WATERLINE OF THE SUBMERGED DOCK SO AS TO PROVIDE SUFFICIENT BALLAST TO MAINTAIN SAID PREDETERMINED UPLOAD FORCE OF SAID DOCK AGAINST SAID HULL; AFFIXING THE UNIT IN POSITION ON THE SHIP HULL; INCREASING THE DRAFT OF THE DOCK BY FLOODING THE CENTER SECTION, WHEREBY THE DOCK MAY BE REMOVED FROM UNDER THE SHIP AND THE ATTACHED UNIT. 